Hydrothermal doping method for preparation of Cr3+-TiO2 photocatalysts with concentration gradient distribution of Cr3+
Hydrothermal doping method for preparation of Cr3+-TiO2 photocatalysts with concentration gradient distribution of Cr3+
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DOI：
10.1016/j.apcatb.2005.08.013
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发表时间：
2006-02
影响因子：
22.1
通讯作者：
Jiefang Zhu;Zhigan Deng;Feng Chen;Jinlong Zhang;Haijun Chen;M. Anpo;Jiazhen Huang;Lizhong Zhang
中科院分区：
文献类型：
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作者：
Jiefang Zhu;Zhigan Deng;Feng Chen;Jinlong Zhang;Haijun Chen;M. Anpo;Jiazhen Huang;Lizhong Zhang
采用溶胶-凝胶法制备了掺杂Cr3+的锐钛矿型二氧化钛光催化剂。采用紫外-可见漫反射光谱、x射线衍射（XRD）、布鲁诺尔-埃米特-泰勒（BET）比表面积（SBET）、透射电镜（TEM）、原子吸收火焰发射光谱（AAS）、电子顺磁共振（EPR）光谱和x射线光电子能谱（XPS）对样品进行了表征。结果表明，Cr在TiO2晶格中以三价离子态取代Ti4+，掺杂剂Cr3+的浓度由外向内递减。研究了cr - tio2在紫外光和可见光照射下光催化降解XRG水溶液的活性。由于Cr3+的三维电子激发到TiO2的导带，cr -TiO2表现出良好的吸收可见光降解XRG的能力。铬离子的掺杂能有效提高紫外光和可见光下的光催化活性，最佳掺杂浓度分别为0.15%和0.2%。掺杂剂Cr3+的特殊分布似乎对增强Cr-TiO2的光催化活性有很好的作用。
Cr3+-doped anatase titanium dioxide photocatalysts were prepared by the combination of sol–gel process with hydrothermal treatment. The samples were characterized by UV–vis diffuse reflectance spectroscopy, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area (SBET), transmission electron microscopy (TEM), atomic absorption flame emission spectroscopy (AAS), electron paramagnetic resonance (EPR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was confirmed that Cr substitutes Ti4+in TiO2lattice in trivalent ionic state, and the concentrations of dopants Cr3+decrease from the exterior to the interior of doped TiO2. The photocatalytic activity of Cr-TiO2was investigated for the photocatalytic degradation of XRG aqueous solution both under UV and visible light irradiation. Due to the excitation of 3d electron of Cr3+to the conduction band of TiO2, Cr-TiO2shows a good ability for absorbing the visible light to degrade XRG. Doping of chromium ions effectively improves the photocatalytic activity under both UV light irradiation and visible light irradiation with an optimal doping concentration of 0.15% and 0.2%, respectively. The special distribution of dopants Cr3+seems having a good effect on enhancing the photocatalytic activity of Cr-TiO2.